Aboriginal and Torres Strait Islander women and breast cancer

Researchers have sought to improve our understanding of why Aboriginal and Torres Strait Islander women (respectfully referred to hereon as Aboriginal) with breast cancer can have poorer outcomes than non-Aboriginal women.

Their study was co-designed with the Aboriginal community and sought to better understand why Aboriginal women in Victoria have both higher breast cancer incidence and mortality rates than non-Aboriginal women with breast cancer.

Data were obtained from the Victorian Cancer Registry (VCR) for 395 Aboriginal women, and more than 57,000 non-Aboriginal women, who were all diagnosed with breast cancer from 2008 to 2021.

Analysis of the VCR data showed that Aboriginal women:

• were significantly younger (median age 56 years vs. 61 years for non-Aboriginal women) at diagnosis and had more advanced stage disease
• were significantly more likely to live in areas of greatest socioeconomic inequity and significantly more likely to live outside of the greater Melbourne area, compared to non-Aboriginal women
• had a 27% increased risk of all-cause mortality (after adjustment for age), compared to non-Aboriginal women

These findings are detailed in a paper titled “Australian Aboriginal and Torres Strait Islander females and survival from breast cancer,” which has just been published in the journal Cancer Epidemiology, Biomarkers & Prevention.

First author, Dr. Alice Bergin, a medical oncologist who is completing her Ph.D. studies at Peter Mac, says the study highlights the need to “address socioeconomic inequities and ensure culturally safe health care.”

“Understanding these outcome disparities requires research which is led and co-designed by the Aboriginal community,” Dr. Bergin also says.

The study involved national collaboration with a team of clinicians, scientists, researchers and Aboriginal women from Western Australia (Fiona Stanley Hospital; Harry Perkin’s Institute; University of Western Australia), Victoria (Professor Sherene Loi and the Loi laboratory, Peter Mac) and Queensland (Professor Gail Garvey, University of Queensland).

The researchers also assessed the level of stromal Tumor-Infiltrating Lymphocytes (sTILs)—a marker of immune response—present in samples of archival, early-stage breast cancers from Aboriginal women from Western Australia.

This immune infiltrate was significantly reduced in breast cancers from Aboriginal women that were hormone-receptor-positive and triple-negative subtypes, when compared to publicly available data from the Cancer Genome Atlas. Further work is currently underway to understand the nature and composition of this infiltrate.

Breast cancer is Australia’s most common cancer in women and approximately 21,000 new cases will be diagnosed in 2025 alone.